McClain dealt with his family being homeless at one point and spent a year at a community shelter. He was often teased by other children because of his clothing since his family was extremely limited financially.

"Bullying is such a broad term for me," McClain told The Baltimore Sun. "I think it affects people on so many levels. When I was a kid, I saw it from something as simple as the clothes I would wear, as far as not having confidence in myself when people would pick on me. They had the ability to pick on me because of what I was going through.

"Bullying can be as simple as telling someone they're undersized or can't play this game. I've had a lot of experiences. Words last longer than bruises. I can remember fights I went through as a kid where I didn't feel it when I got hit in my stomach. You don't feel that pain or that bruise, but I remember what people said. I remember things meant to bring me down."

According to Stomp Out Bullying, one of four children is bullied. At least 43 percent of young people say they've been victims of cyberbullying. And nine of 10 LGBT students said they're harassed at school.

Suicides have been attributed to bullying and cyberbullying.

"I hope people can listen to me and embrace me not because of the things I've been able to accomplish on the football field, but because of the tthings I've been able to accomplish as a person," said McClain, who was joined as a global ambassador by Sports Illustrated swimsuit model Alyssa Miller. "I've been able to look negativity in the eye. I felt like I would be ideal for this program to step up and better the world.

"What better person to listen to than to someone who's been through the majority of the hard circumstances? I know people have been through more than me, but I'm glad to be able to shed light on my experiences. It's to share and help others. Why not share?"

McClain, who's in the process of finishing plans for a football and education camp in the Baltimore area in early July, said it's about raising awareness for this issue.

"Bullying takes on so many forms, in the workplace, in social networking," McClain said. "I know a child that went through a bullying incident in Philadelphia who's a fan of mine that's connected through family. For the child to be bullied and get into an altercation that ended with kids posting it on the Internet, it's so crazy. But it happens, and it's so unfortunate. And it can be stopped. It's about making people aware of what they're doing and why it needs to stop."